1. Field of the Invention
The present invention relates to a semiconductor integrated circuit including a non-volatile device, and more particularly, to a technique for testing the non-volatile device.
2. Description of the Related Art
As a technique for testing a non-volatile device storing confidential information which is included in a semiconductor integrated circuit, there is a known technique in which confidential data stored in a ROM is subjected to a predetermined computation, such as cyclic redundancy check (CRC) or the like, the result of the computation is compared with redundant data for checking (hereinafter referred to as check redundant data) which is the result of a predetermined computation which is previously executed with respect to the confidential data, and the result (match or mismatch) of the comparison is output to the outside (see Japanese Unexamined Patent Application Publication No. 2001-344992). With the technique, the ROM can be tested without outputting the confidential information stored in the ROM to the outside.
However, in the conventional technique, even if an error is found, it cannot be determined whether the error is of the confidential data in the non-volatile device or of the check redundant data. Also, since a bit in which the error occurs cannot be detected, it is difficult to analyze a factor in the error.